التفاصيل البيبلوغرافية
العنوان: |
Investigation on the role of indium in the removal of metallic gallium from soft and hard sputtered GaN (0001) surfaces |
المؤلفون: |
Agnarsson, B.1,2 bjornagn@kth.se, Qi, B.2, Szamota-Leandersson, K.1, Olafsson, S.2, Göthelid, M.1 gothelid@kth.se |
المصدر: |
Thin Solid Films. Sep2009, Vol. 517 Issue 21, p6023-6026. 4p. |
مصطلحات موضوعية: |
*SURFACE chemistry, *INDIUM, *SPUTTERING (Physics), *GALLIUM nitride, *FERMI surfaces, *BAND gaps, *EPITAXY, *PHOTOEMISSION, *ELECTRON diffraction |
مستخلص: |
Abstract: Cleaning of GaN by argon sputtering and subsequent annealing introduces metallic gallium on the GaN surface. Once formed, this metallic gallium can be difficult to remove. It has a strong influence on the Fermi level position in the band gap and poses a problem for subsequent epitaxial growth on the surface. We present a method of removing metallic gallium from moderately damaged GaN surfaces by deposition of indium and formation of an In–Ga alloy that can be desorbed by annealing at ~550 °C. After the In–Ga alloy has desorbed, photoemission spectra show that the Ga3d bulk component becomes narrower indicating a smoother and more homogeneous surface. This is also reflected in a sharper low energy electron diffraction pattern. On heavily damaged GaN surfaces, caused by hard sputtering, larger amount of metallic gallium forms after annealing at 600 °C. This gallium readily alloys with deposited indium, but the alloy does not desorb until a temperature of 840 °C is reached and even then, traces of both indium and metallic gallium could be found on the surface. [Copyright &y& Elsevier] |
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